Particle Physics - 3ds max

Chris2005

Someone requested me to do the Voyager Title Credits, and in one shot, Voyager is passing through a gas like cloud, with particles interacting, and changing colors, as they appear to be deflected by the deflector array, I assume.

How can I do this kind of effect in Max, where particles, in a particle cloud will react to an object passing through them...



This shot is 100% CG including Voyager, which I assume was done, for the main reason, it would be easier to make particles react to a deflector of some kind, not sure what it's called in Lightwave.

Melak

There's probably a number of ways you could do it.
Looking at the effect, the easiest approach might be to use a elliptical or even wedge shaped deflector object, make a collision test with that, and let the collided particles be affected by a spherical wind force with decay option set, and turbulence, blowing them away.
Also, reset particle age upon collision, and then use a Particle Age map in the material to alter the color of the particles from a green back to blue over time.

Chris2005

Melak wrote: »

There's probably a number of ways you could do it.
Looking at the effect, the easiest approach might be to use a elliptical or even wedge shaped deflector object, make a collision test with that, and let the collided particles be affected by a spherical wind force with decay option set, and turbulence, blowing them away.
Also, reset particle age upon collision, and then use a Particle Age map in the material to alter the color of the particles from a green back to blue over time.

I kinda get what you're saying, but is their a tutorial for this basic concept? I've not really done much with particle systems...

Melak

Google Allan McKay, he's "pretty good" with PFlow, and he has some old video tutorials on his page somewhere. (Pflow hasn't really changed that much)

Here's a crappy example of how I might set it up:


A UDeflector, choose your sphere/shield/wedge as geometry, and a couple wind forces linked to it, and a box filled with particles
and the PFlow looks like this:

It spawns 10,000 particles before the beginning of the scene, assigns a material (this would be the default nebula blue one) and upon collision the particles die, and new ones get spawned in their place, with their age starting from 0. Then the wind forces are applied, you assign the other material (which changes color for the particles synced by their age)



Edit: of course you might also need to assign a shape to the particles, say facing planes/billboards with a falloff map to get that cloudy look.
Edit, again:
Which might look like this. Though hopefully better :shiner:

Guerrilla

Nice one Leon! I only got as far as 'you could maybe look at Allan Mckay's old stuff'.

Melak

Haha I picked up a thing or two from his tutorials, unfortunately not how to make things look pretty
Thanks for digging that link up

Chris, you should take a look at the "Pflow Basics: Setting Manual Initial State / Pflow Loops" tutorial in particular, Setting an initial state for your clouds would be useful. And it also shows how to get some nice looking turbulence.

And the "Pflow Basics: More particle Effects" one is also useful, it demonstrates how to use a noise map on a sphere to spawn a nice turbulent particle cloud thingy, which could probably be adapted easily to make a nice couple turbulent layers like in the intro sequence there.

Also, to set planets on fire, or something. I suppose.

Chris2005

Melak wrote: »

Google Allan McKay, he's "pretty good" with PFlow, and he has some old video tutorials on his page somewhere. (Pflow hasn't really changed that much)

Here's a crappy example of how I might set it up:


A UDeflector, choose your sphere/shield/wedge as geometry, and a couple wind forces linked to it, and a box filled with particles
and the PFlow looks like this:

It spawns 10,000 particles before the beginning of the scene, assigns a material (this would be the default nebula blue one) and upon collision the particles die, and new ones get spawned in their place, with their age starting from 0. Then the wind forces are applied, you assign the other material (which changes color for the particles synced by their age)



Edit: of course you might also need to assign a shape to the particles, say facing planes/billboards with a falloff map to get that cloudy look.
Edit, again:
Which might look like this. Though hopefully better :shiner:

Melak wrote: »

Haha I picked up a thing or two from his tutorials, unfortunately not how to make things look pretty
Thanks for digging that link up

Chris, you should take a look at the "Pflow Basics: Setting Manual Initial State / Pflow Loops" tutorial in particular, Setting an initial state for your clouds would be useful. And it also shows how to get some nice looking turbulence.

And the "Pflow Basics: More particle Effects" one is also useful, it demonstrates how to use a noise map on a sphere to spawn a nice turbulent particle cloud thingy, which could probably be adapted easily to make a nice couple turbulent layers like in the intro sequence there.

Also, to set planets on fire, or something. I suppose.

Thanks, you're a life saver.

Guerrilla wrote: »

Nice one Leon! I only got as far as 'you could maybe look at Allan Mckay's old stuff'.

haha.

Chris2005

I have the particles all set, which deflector would I use if I wanted to create a bubble like shape around the ship...

Here is my scene so far...



I have Particle View all set up, I just need to know how to get the particles to be affected by the deflectors.

Got it.

ps.
This really brings my viewport performance to a halt... in some instances.

Chris2005

Here is a view so far, again, just crude, as I get a feel for doing this.

I think I'll follow this:
http://www.cgrats.com/create-realistic-clouds-in-3ds-max.html

To get a more realistic look to the clouds.

If I could inquire once more, about particle age, the way they'll change color over time, how do I do that...

Melak

Yeah particle viewport performance can suck a lot
In the "Render" box of the Pflow, just select the box the get a bunch of options, like how many % of the particles you want visible in your viewport, that can speed things up. (default is 50%)

Also, try to avoid scrubbing the time backwards, since it's kind of retarded and basically goes back to the beginning and then simulates again up to the frame you scrubbed to.

For the particle age, you need to add a "delete" operator to your PFLow so that your particles die eventually.
Then, put a particle age map in your diffuse slot or where ever . You'll have 3 colors/map slots available, and can set at what % of particle age they should be shown. It'll interpolate between the colors. You can also nest multiple of these inside of each other if you need more colors.

For your newly spaned wake particles for example:

They will start out green, fade to um, turqoise? at 50% of their lifespan, and back to blue at 75

Chris2005

Melak wrote: »

Yeah particle viewport performance can suck a lot
In the "Render" box of the Pflow, just select the box the get a bunch of options, like how many % of the particles you want visible in your viewport, that can speed things up. (default is 50%)

Also, try to avoid scrubbing the time backwards, since it's kind of retarded and basically goes back to the beginning and then simulates again up to the frame you scrubbed to.

For the particle age, you need to add a "delete" operator to your PFLow so that your particles die eventually.
Then, put a particle age map in your diffuse slot or where ever . You'll have 3 colors/map slots available, and can set at what % of particle age they should be shown. It'll interpolate between the colors. You can also nest multiple of these inside of each other if you need more colors.

For your newly spaned wake particles for example:

They will start out green, fade to um, turqoise? at 50% of their lifespan, and back to blue at 75

Thanks.

Yea, I noticed that scrubbing backward issue, you can scrub smoothly forward, but not backward...

Melak

Since you have mostly flat layers of nebula here, you could probably still use a noise map or an actual cloud texture to spawn your particles, and use that tutorials way of setting up the materials so that they look nice

Example: simple noisemap as in that one video tutorial, but rendered as spheres so you can make out the shape

Chris2005

Melak wrote: »

Since you have mostly flat layers of nebula here, you could probably still use a noise map or an actual cloud texture to spawn your particles, and use that tutorials way of setting up the materials so that they look nice

Example: simple noisemap as in that one video tutorial, but rendered as spheres so you can make out the shape

Neato.

L2K

when playing with PF, you WANT to add a cache operator on the root.

Chris2005

L2K wrote: »

when playing with PF, you WANT to add a cache operator on the root.

What does that do?

IRML

looking at the previous page I think you could do with attaching a wind effector at the back of the collision object, you can set that up to make the paticles move behind the ship like they do in the show

Chris2005

IRML wrote: »

looking at the previous page I think you could do with attaching a wind effector at the back of the collision object, you can set that up to make the paticles move behind the ship like they do in the show

Yea, really haven't gotten that far yet, I'm still trying to get the particles to look decent, lol.

L2K

cache operator would put your particles into a cache.
so it calculates it once and youre free to scrub your timeline forwards and backwarrds without calculation.

also, when playing into your particle window, be sure to come back to frame 0, or you'll wait forever for anything you touch.

Melak

Duh, cache operator, of course! Thanks L2K

Once you get to adding the wind force(s), you could try using a spherical wind force with 0 strength, 0.1 turbulence, and small scale setting to get large, wavy turbulence going. This will affect all the collided particles regardless of distance though, so you might want to add an Age Test operator and then apply a Drag force in the next Event, so your particles gently slow down some time after the collision.